The Chronicle’s front page from Aug. 21, 1968, covers the Soviet-led invasion of Czechoslovakia after a push for liberalization reforms.

“Czechoslovakia was occupied early today by troops of the Soviet Union and her Warsaw Pact allies in a series of swift land and airborne movements,” read the New York Times story, which, per the custom of the time, used female pronouns in reference to nations. “Unconfirmed reports said two Czechoslovak soldiers and a woman were killed by Bulgarian tank fire in an affray in front of the Radio Prague building shortly before the station finally was captured and went off the air.”

More than 100 Czech and Slovak civilians were killed in the invasion by 250,000 soldiers, which included troops from Bulgaria, Poland and Hungary, as well as the USSR.

“The Soviet invasion of Czechoslovakia has transformed world and American politics,” a New York Times analysis of the news read. “It took place in the middle of the American presidential election just as the Soviet invasion of Hungary took place during the Eisenhower-Stevenson presidential election of 1956.

“The Soviets moved on Prague while the United States was preoccupied in Vietnam, as they moved on Budapest in 1956 while the British and French were preoccupied with the invasion of Suez.”

The operation would quell an uprising known as the Prague Spring and strengthen the authoritarian control over the country. The Soviet military presence would remain in Czechoslovakia until 1991.

See more front pages: Go to SFChronicle.com/covers to search a database of hundreds of Chronicle Covers articles from the newspaper’s history.